Drive for a Symmetrical Two-Phase Induction Machine Using Vector Modulation

-Two PWM techniques using space vector pulse-width modulation (SVPWM) are proposed for a two-phase permanent magnet synchronous motor (PMSM) driven by a two-phase eightswitch inverter. A two-phase motor with two symmetric stator windings is usually driven by a twophase four-, six-, or eight-switch inverter. Compared with a four-and six-switch inverter, a two-phase eight-switch inverter can achieve larger power output. For two-phase motor drives, the SVPWM technique achieves more efficient DC bus voltage utilization and less harmonic distortion of the output voltage. For a two-phase PMSM fed by a two-phase eight-switch inverter under a normal SVPWM scheme, each of the eight PWM trigger signals for the inverter have to be changed twice in a cycle, causing a higher PWM frequency. Based on the normal SVPWM scheme, two effective SVPWM schemes are investigated in order to reduce the PWM frequency by rearranging four comparison values, while achieving the same function as the normal PWM scheme. A detailed explanation of the normal and two proposed SVPWM schemes is illustrated in the paper. The experimental results demonstrate that the proposed schemes achieve a better steady performance with lower switching losses compared with the normal scheme.

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Space-vector PWM Techniques for a Two-Phase Permanent Magnet Synchronous Motor Considering a Reduction in Switching Losses

Lin¹,

Zhao²,

Kwon³

2015

“…In the fan application, the two-phase BLDC motor with sinusoidal back-EMFs is widely preferred to reduce manufacturing costs [10,11]. In this paper, based on the traditional PWM strategies of the three-phase BLDC motor drive, two normal PWM schemes are investigated for the two-phase BLDC motor drive.…”

Section: Introductionmentioning

confidence: 99%

New PWM Technique for Two-Phase Brushless DC Motor Drives

Lin¹,

Kwon²

2013

-A new PWM technique for a two-phase BLDC motor fed by a two-phase eight-switch inverter is proposed in this paper. It is well known that a two-phase eight-switch inverter can significantly improve power output compared with a two-phase six-switch inverter in a two-phase motor drive. To drive the two-phase BLDC motor simply and effectively, two normal PWM strategies are investigated to manage speed regulation. However, under the conditions of low speed and light load, especially during the braking process, the current in a short time of one period is near zero, which is a discontinuous waveform every half period. To solve it, a novel PWM technique is investigated to improve the operational performance of normal technique. Using the new PWM scheme, the current continues every half period and the braking performance is improved. The effectiveness of the proposed PWM method is verified through the experiments.

“…However, to balance the third common end of the two-phase motor, two capacitors in the inverter are necessary, which increases the total cost. In terms of cost, the six-switch inverter is a compromise among the three types of inverters [10][11][12]. Better steady performance and low noise are achieved while keeping the third common end of the motor under control.…”

Section: Introductionmentioning

confidence: 99%

Digital Implementation of PWM Techniques for Two-phase Eight-switch Inverter fed Brushless DC Motor Drives

Lin¹,

You²,

Cheon³

et al. 2013

-This paper reports an investigation of pulse width modulation (PWM) techniques fo r two-phase brushless DC (BLDC) motors fed by a two-phase eight-switch inverter in a fan a pplication. The three-phase BLDC motor is widely applied in industry; however, a lower-cost t wo-phase BLDC motor and drive circuit has been greatly in demand in recent years. In this p aper, we introduce a mathematical model of the two-phase BLDC motor with sinusoidal back electromotive forces (EMFs) based on traditional three-phase BLDC motors. To simplify the dr ive algorithm and speed up its application, we analyze the principle of block commutation for a two-phase BLDC motor drive in the 180-electrical-degree conduction mode, and we further propose five PWM schemes to improve the commutation performance of the two-phase BLDC drive. The effectiveness of the proposed PWM methods is verified through experiments.